Removing unneeded timezones from bundle

[bteng22]

Sorry if this is a trivial question/if this isn't the correct avenue, but is there any way to remove timezones and locales that are unused? My team and I only need to determine the time in the America/New York timezone, but it seems this library is pulling in packages related to every other available timezone/locale.

Here is how we're currently using the library:

import tz from 'timezone'

const getESTHours = (date) => {
  const US = tz(require('timezone/America'))
  const currentESTHour = US(date, 'America/New_York', '%H')
  return parseInt(currentESTHour, 10)
}

And here's a screenshot of our bundle analysis, where the timezone module has contributed to a huge percentage of our bundle size.

We figured Webpack's tree shaking feature with UglifyJsPlugin would have automatically removed them if they were unused, but we wanted to drop a note here just in case anyone else has run into this before.

Any help would be super appreciated! ✊

[leedstyh]

The bundle size is too big for me too, but I also need them as the user can switch timezone in my app. So import them dynamically as needed is a better choice?

[webschik]

@bteng22 , did you try to include a timezone in the next way?

import tz from 'timezone'

const getESTHours = (date) => {
  const US = tz(require('timezone/America/New_York')); // include only your specific timezone
  const currentESTHour = US(date, 'America/New_York', '%H')
  return parseInt(currentESTHour, 10)
}